Head-to-head
ChatGPT‑6 vs Claude Opus 5
Claude Opus 5 is the polished, expensive flagship with a huge context. ChatGPT-6 comes very close on quality and does it for free during preview.
Anthropic
Claude Opus 5 is Anthropic's top-tier model — exceptional at hard coding and long-form writing, with a 1M-token context, and priced for enterprises that treat quality as the only variable. ChatGPT-6 trades within a few points on the benchmarks, edges ahead on agentic coding, and costs $0 while in early access. If budget matters at all, the gap is hard to justify.
Side by side
The same figures from our full benchmark table, narrowed to two columns.
| Metric | ChatGPT-6 | Opus 5 |
|---|---|---|
| Intelligence Index | 71* | 68 |
| Agentic coding | 86* | 82 |
| Context window | 400K | 1M |
| Max output | 128K | 64K |
| Throughput (tps) | 58* | 55 |
| Price / 1M out | $0 | $25 |
| Multimodal | ||
| Open weights | ||
| Free to use |
- Free during preview — Opus 5 runs about $25 per million output tokens
- Higher agentic-coding score
- Double the max output (128K vs 64K tokens)
- No account, no card, no app to get started
- Larger context window (1M vs 400K)
- A stable, officially-supported API with an SLA
- Best-in-class polish on long-form writing
Which should you choose?
You want frontier-class reasoning and coding for free, and 400K context is plenty.
You need the very largest context and a production guarantee today.
Try ChatGPT-6 free
No account, no card, no app — open the chat and compare for yourself.